/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/AssetUtils/Texture2DBuilder.h
Set the texel at the given X/Y coordinates to the givenFColor
void SetTexel ( const [FVector2i](API\Runtime\GeometryCore\FVector2i) & ImageCoords, const [FColor](API\Runtime\Core\Math\FColor) & NewValue )